This application claims the benefit of Korean Application No. 2003-5181, filed Jan. 27, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates, in general, to a high voltage transformer and, more particularly, to a high voltage transformer provided with a temperature sensor to sense a temperature of a coil of the transformer.
2. Description of the Related Art
A high voltage transformer is a device that functions to boost an input voltage supplied from an external power supply to a high voltage and output the boosted voltage, and is generally used in electronic products such as a microwave oven.
The high voltage transformer is manufactured by joining a laminated E core, in which a plurality of E iron cores are laminated, with a laminated I core, in which a plurality of I iron cores are laminated, and disposing electrical parts such as a primary coil and a secondary coil between the laminated E core and the laminated I core.
Generally, the high voltage transformer is electrically connected between the external power supply and a load, functions to boost voltage supplied from the external power supply, and supplies the boosted voltage to the load. If the high voltage transformer is heated, a temperature of the secondary coil of the transformer connected to the load is excessively increased.
A high voltage transformer utilized in electronic products operated using a high voltage such as a microwave oven, is provided with a temperature sensor to prevent overheating. The temperature sensor is disposed in a vicinity of the secondary coil of the transformer to control an operation of the transformer based on the temperature of the secondary coil. The temperature sensor is electrically connected in series to the primary coil of the transformer. If the temperature of the secondary coil is equal to or higher than a preset temperature, the operation of the high voltage transformer is stopped by cutting off power supplied to the primary coil.
The temperature sensor that senses the temperature of the secondary coil of the high voltage transformer is installed by hand. Thus, the temperature sensor is disposed in the vicinity of the secondary coil without being fixed. If the temperature sensor is moved from an initial position, it is difficult to correctly sense the temperature of the secondary coil. Accordingly, there is an inconvenience in that it is determined whether the temperature sensor is disposed in the initial position at a time of manufacturing the high voltage transformer.
Additionally, although the temperature sensor is disposed in the initial position at the time of manufacturing the high voltage transformer, the temperature sensor may be moved from the initial position due to vibration which may be generated during the operation of the high voltage transformer. Accordingly, a method of stably installing the temperature sensor and correctly sensing the temperature of the secondary coil is needed.
Accordingly, it is an aspect of the present invention to provide a high voltage transformer to prevent a shifting of a position of a temperature sensor, thereby correctly sensing a temperature of a coil of the transformer.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
The foregoing and/or other aspects of the present invention are achieved by providing a high voltage transformer including a core, a coil disposed in the core, a temperature sensor to sense a temperature of the coil, and a fastening unit to fixedly attach the temperature sensor to the core.
According to an aspect of the invention, the fastening unit includes a shield cover to allow the temperature sensor to be fitted therein, and a rivet to fasten the shield cover to the core.
The shield cover includes a fastening hole to allow the rivet to penetrate therethrough.
The fastening unit fixedly attaches both the shield cover and a ground element that grounds the coil.
The shield cover is made of an insulating material.
The foregoing and/or other aspects of the present invention are achieved by providing a high voltage transformer including an E core and an I core joined together, and a primary coil and a secondary coil. The secondary coil is disposed in a space provided in the E core. The high voltage transformer also includes a temperature sensor to sense a temperature of the secondary coil, a shield cover to allow the temperature sensor to be fitted therein, and a rivet to fixedly attach the shield cover to the E core.
The shield cover includes a fastening hole to allow the rivet to penetrate therethrough.
The rivet fixedly attaches both the shield cover and a ground element that grounds the secondary coil to the E core.
The shield cover is made of an insulating material.